As a consequence of PM-2423, write operations to orphan documents have no effect on the actual data, leaving it unchanged on disk and waiting for range deleter to do its job.
The exact_shard_key_target.js test verifies that shard key targeted update/delete operations go to exactly one shard when targeted by nested shard keys. This is currently based on explicit insertion of orphan documents, requiring now additional logic to properly handle the new behavior of writes to orphans.
Evaluate a new implementation in order to achieve the same test's goals without using orphan documents.
Refer to this comment for more information on the requirement.